Scale traps for a pipe



oct. 1o, 1967 M. l.. WITT l SCALE TRAPSl Fon A PIPE Filed oct, 15, 1963 WWW? I/VVENTOI? MERLIN L. WIT'T 5%@ www ATTORNEY United States Patent O 3,346,123 SCALE TRAPS FOR A PIPE Merlin L. Witt, 1005 W. 3rd Ave., Brodhead, Wis. 53520; Dorothy Witt, executrix olf said Merlin L. Witt, deceased Filed Oct. 15, 1963, Ser. No. 316,476 4 Claims. (Cl. 210-532) My invention relates to an improved scale trap for a pipe.

Well systems employing submersible pumps are cornmonly used today to supply water. An annoying problem aften attends the use of such submersible pumps. Over a prolonged period of operation, the well delivery pipe leading from the submersible pump tends to deve'lop a scale on its interior surface. Eventually this scale akes free of the pipe and falls through the pipe to the submersible pump. It there drops into a ycheck valve usually attached to the pump and may even work its way into the pump itself. The efficiency of the check valve and the pump is consequently reduced. In Yextreme cases the scale may damage the pump. Any repair or cleaning of the pump which may become necessary is costly and laborious because the pump is submerged in the well at a considerable distance from the ground surface. v

It is a primary object of my invention to provide a device which prevents the scale that forms in a well delivery pipe from in any way interfering with the efficient operation of a submersible pump -or other equipment located Within the well pipe;

Another object of my invention is to provide a device which traps any scale that may form in a pipe to prevent it from clogging a submersible pump or other elements located within the pipe.

A further object of my invention is to provide for a pipe a novel scale trap that is economical to manufacture and is usable with any kind of submersible pump or other equipment.

Other objects and advantages of my invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings wherein a preferred embodiment of the principles of the invention has been selected for exempliiication.

In the drawings:

FIG. l is a partially schematic section view of a Well system with a submersible pump.

FIG. 2 is a section view of one embodiment of my novel scale trap.

The well system shown schematically in FIG. 1 comprises a motor 8, a submersible pump with an .intake port 9 and an outlet port 11, a nipple 21,'a water delivery pipe 12 and my novel scale trap 13, `all of which are enclosed by the well casing 7. Water or other fluid is pumped by the pump 10 in an upwardly direction to the outlet end 15 of the pipe 12, where it is discharged.

. The scale trap 13 of FIG. 1 includes an outer body or pipe 14 having an upper end 14a adapted to engage the delivery pipe 12 in any suitable manner, a cylinder 22 located within the outer body 14 and having its upper end 23 closed by a cap 24, anda coupling 16 which engages the lower end 14b of the trap outer body 14. The lower end 19 of the cylinder 22 is preferably attached to the coupling 16 by means of a short cylindrical adapter 25 which is soldered or otherwise suitably joined to the cylinder 22. The cylinder adapter 25, which has a thicker wall than does the cylinder 22, is adapted to be easily threaded without deformation. Approximately the upper half of the cylinder 22 carries a plurality of slots 26. These slots 26 are preferably grouped in columns which are spaced around the circumference of the cylinder 22. The opening in the cylinnder 22 provided by the slots 26 must be suf- ICC ficient to allow the passage of water or other fluid at the rate pumped by the submersible pump 10.

The coupling 16 connects in proper relation the nipple 21, the trap outer body 14 and the cylindrical adapter 25. The coupling 16 has a substantially cylindrical portion 17 and a lower shoulder 18. Both the interior and exterior surfaces of the cylindrical portion 17 are threaded. The shoulder 18 is preferably hexagonal in outline to facilitate easy gripping of it by a wrench.

The adapter 25 of the scale trap 13 is externally threaded for engagement with the threads on the interior of the coupling 16 near its top 16a. The lower end 14b of the outer body 14 is internally threaded for engagement with the threads on the exterior surface of the coupling 16. The nipple 21 is externally threaded for engagement with the threads on the interior of the coupling 16 near its bottom 16h.

As is clear from the description of the connection of the trap outer body 14, the cylinder 22 and the coupling 16, the inside -diameter of the outer body 14 is larger than the outside diameter of the cylinder 22. An annular space 27 closed at one end by the coupling 16 is formed when the outer body 14 and the adapter 25 are attached to their respective portions by the coupling 16. The width of the annular space 27 is determined by the wall thickness at the top 16a of the coupling 16, where the adapter 25 threadedly engages the coupling 16. The upper end 16a of the illustrated coupling 16 has a smaller internal diameter than does the lower end 16b of the coupling. This construction increases the width of the annular space without restricting the diameter of the nipple 21. However, the internal diameter of the coupling 16 may be the same at both ends, if desired.

The nipple 21, the cylinder 22, the cap 24 and the adapter 25 are constructed of a material which does not develop a scale on contact with water or with whatever other iluid i-s carried through the scale trap 13. When the iluid is water, a preferred material for these elements is brass.

The scale trap 13 works with 'surenesa Water ows out of the pump 10 through its outlet port 11 and the nipple 21 and into the cylinder 22 at its lower end 19. The water leaves the cylinder 22 through the slots 26 and then flows through the outer body 14 to the water pipe 12. In time, scale may form on the interior surface of the pipe 12 and flake f-ree of the surface. But the scale is unable to drift down to the pump 10 to interfere with its efficient operation. The careful design of scale trap 13 prevents the scale from entering the cylinder 22 and thereby reaching the pump 10. The cap 24 stops any scale from entering the top of the cylinder 22. The slots 26 are sutliciently small so that any scale of suitable size and shape to harm the pump 10 or associated check valve is substantially prevented from entering the cylinder 22 through its side walls. The scale is only able to drift and settle in the lower end 20 of the annular space 27 between the cylindrical adapter 25 and the trap outer body 14.

A substantial amount of scale may eventually accumulate in the bottom of the annular space 27. But there will not be accumulated in the conceivable life of the Well system sufficient scale to reach the level of the slots 26 in the cylinder 22 and clog them. The placement of the slots 26 in the approximate upper half of the cylinder 22 renders such clogging almost impossible.

In the embodiment of my scale trap 13 just described, the trap outer body 14 is an element distinct from the water pipe 12. An alternative embodiment may be used in which the trap outer body 14 is eliminted. In the alternative embodiment the water pipe 12 is internally threaded for direct engagement with the threads on the exterior surface of the coupling 16, as shown in FIG. 2.

The annular space 27 then exists between the cylinder 22 and the water pipe 12 instead of between the cylinder 22 and the trap outer body 14. Whether or not a distinct trap outer body 14 is used, operation of the scale trap 13 is the same.

The scale trap 13 is primarily a gravity trap. It works best when placed in a substantially vertical position. But it also works effectively in Vany position that is inclined to the horizontal.

My scale trap 13 traps both scale and any other foreign matter that may appear in the well pipe 12 equally Well. Furthermore, it is not limited to use with a submersible pump. It may be advantageously used with any piece of equipment which must be kept free of scale or other harmful foreign matter.

It is understood that my invention is not confined to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modied forms thereof as come within the scope of the following claims.

I claim:

1. A scale trap comprising a cylinder with a lower end and an upper end, said lower end being open for the entry of uid and said upper end being closed by a cap, said cylinder having a plurality of slots spaced axially along a substantial axial portion of said upper end, and a substantial axial portion of said lower end being impervious, said slots being adapted to allow the passage of fluid from the inside of said cylinder to the outside of said cylinder, means at the lower end of said cylinder to mount said cylinder in a pipe larger than said cylinder whereby an annular space is dened between said cylinder and said pipe, said mounting means closing said annular space at said lower end of said cylinder.

2. The scale trap of claim 1 wherein the mounting means holds the cylinder in an approximately vertical position.

3. In combination, a pipe and a scale trap, said scale trap comprising a cylinder with a lower end open for the entry of fluid and an upper end closed by a cap, the outer diameter of said cylinder being smaller than the inner diameter of said pipe, means at the lower end of said cylinder to mount said cylinder within said pipe to dene an annular space between said cylinder and said pipe, said means closing said annular space at said lower end of said cylinder whereby uid is unable to enter said pipe through said annular space at said lower end of said cylinder, said cylinder having a plurality of slots spaced axially along a substantial axial portion of said upper end whereby fluid is able to leave said cylinder and enter saidfpipe and a substantial axial portion at said lower end which is fluid impervious, the slotted portion of said cylinder extending for at least one-half the axial length thereof.

4. The invention of claim 3 wherein the means for closing the annular space at the lower end of the cylinder comprises a substantially cylindrical coupling containing a passage, said lower end of said ycylinder being threadedly engaged with said coupling in communication with said passage, and the pipe being threadedly engaged with the exterior surface of said coupling.

References Cited UNITED STATES PATENTS 916,340 3/1909 Lewis 210-448 2,078,543 4/ 1937 Salisbury 210-448 2,779,478 1/ 1957 Wahlin 210-448 3,072,261 1/1963 Smith 210-532 FOREIGN PATENTS 548,395 10/ 1942 Great Britain.

REUBEN FRIEDMAN, Primary Examiner.

F. MEDLEY, Assistant Examz'neri 

1. A SCALE TRAP COMPRISING A CYLINDER WITH A LOWER END AND AN UPPER END, SAID LOWER END BEING OPEN FOR THE ENTRY OF FLUID AND SAID UPPER END BEING CLOSED BY A CAP, SAID CYLINDER HAVING A PLURALITY OF SLOTS SPACED AXIALLY ALONG SUBSTANTIAL AXIAL PORTION OF SAID UPPER END, AND A SUBSTANTIAL AXIAL PORTION OF SAID LOWER END BEING IMPERVIOUS, SAID SLOTS BEING ADAPTED TO ALLOW THE PASSAGE OF FLUID FROM THE INSIDE OF SAID CYLINDER TO THE OUTSIDE OF SAID CYLINDER, MEANS AT THE LOWER END OF SAID CYLINDER TO MOUNT SAID CYLINDER IN A PIPE LARGER THAN SAID CYLINDER WHEREBY AN ANNULAR SPACE IN DEFINED BETWEEN SAID CYLINDER AND SAID PIPE, SAID MOUNTING MEANS CLOSING SAID ANNULAR SPACE AT SAID LOWER END OF SAID CYLINDER. 